Boop

A monotone sound made when conversations stall. Sometimes responded to with "beep", both in varying length and volume.

The use of Boop can be accredited to the Spongebob Squarepants episode "Your Shoe's Untied", in which the Flying Dutchman shows Spongebob various ways to tie knots, including the "Poop Loop", which emits a high-pitched noise that sounds like the word "poop" as it is pulled loose. Boop is an onomatopoeic variation of poop.